1. Field of the Invention
The present invention relates to a motor and a hard disk drive including the same, and more particularly, to a motor capable of preventing low pressure from being generated in a thrust dynamic pressure part, and a hard disk drive including the same.
2. Description of the Related Art
A hard disk drive (HDD), an information storage device, reads data stored on a disk or writes data to a disk using a read/write head.
The hard disk drive requires a disk driving device capable of driving the disk. In the disk driving device, a small-sized spindle motor may be used.
The small spindle motor commonly uses a hydrodynamic bearing assembly. A lubricating fluid is interposed between a shaft and a sleeve of the hydrodynamic bearing assembly, such that the shaft is supported by fluid pressure generated in the lubricating fluid.
A thrust bearing may be formed between a rotor and the sleeve of the hydrodynamic bearing assembly to smoothly support rotation of the rotor.
Here, the lubricating fluid may flow smoothly by the thrust bearing inwardly in a radial direction.
Here, in the case in which a width of a clearance between the rotor and the sleeve is changed, low pressure may be generated in a location in which the clearance is a relatively narrow while the lubricating fluid passes through the clearance, such that air bubbles may be generated in the lubricating fluid as the low pressure is generated.
Since this is closely associated with the performance of the motor, research into a technology for suppressing the generation of low pressure has been urgently demanded.
In the related art described in the following Patent Document, since a clearance is narrow in a location in which a thrust dynamic pressure groove is formed, low pressure may still be generated.